Hydrocarbon oils containing ashless dispersant inhibitors



United States Patent HYDROCARBON OILS CONTAINING ASHLESS DISPERSANTINHIBITORS Joel R. Siegel, Irvington, NJ., assignor to Esso Research andEngineering Company, a corporation of Delaware No Drawing. Filed Dec. 6,1956, Ser. No. 626,590

6 Claims. (Cl. 44-62) The present invention is directed to thestabilization of hydrocarbon oils and particularly of petroleumdistillates against discoloration and the formation of sediment duringstorage. More particularly, the invention concerns the stabilization ofhydrocarbon fuel oils during storage by incorporating into the oilsaddition agents that inhibit degradation of the fuel oils and which atthe same time serve to disperse any sediment producing materials thatmay have formed in the fuel oil. These addition agents are of particularvalue because they do not form ash or residues when the fuel oils areburned.

The hydrocarbon fuel oils with which this invention is particularlyconcerned broadly comprise petroleum distillates that are commonlyemployed in various burner systems, as fuels for diesel engines, as jetfuels and as domestic or industrial heating oils. These fuel oils may begenerally characterized as those that consist of a major proportion ofhydrocarbons boiling in the range of from about 350 F. to about 900 F.It is common practice to incorporate cracked hydrocarbon stocks in suchfuel oils, and this practice aggravates the tendency of the fuel oils toform sediment on storage. It has been found that if 10 percent or moreof the fuel oil composition comprises cracked stocks, the formation ofsludge or sedi ment during storage may be markedly increased, leading tothe plugging or fouling of oil lines, filters and burner nozzles.

Attempts have been made in the past to overcome the sediment-formingproblem by incorporating in the fuel oils various addition agents, someof which have met with a degree of success. Many of these additives,however, particularly metal salts such as metal naphthenates, metalsulfonates and metal salts of alkyl phenol sulfides, have beenobjectionable in that they leave an ash residue on combustion.

It is a primary object of this invention to improve the stability ofpetroleum hydrocarbon fuel oils against the formation and precipitationof sediment while at the same time minimizing the formation of ash whensuch fuels are burned. It is an additional object of the invention toimprove the color stability of such fuel oils.

It is still a further object of this invention to provide improvedaddition agents, and improved methods of preparation of the same, foraccomplishing the objects stated above.

In accordance with the present invention, the sedimentforming tendenciesof petroleum hydrocarbon oils, and particularly of fuel oils, can bemarkedly reduced by incorporating therein minor proportions, of theorder of from about 0.001% to about 0.2%, of a polymeric materialcontaining an azomethine linkage. The polymeric materials of thisinvention are preferably prepared by copolymerizing a mixture of threetypes of monomeric materials, namely, a long chain alcohol ester of aconjugated unsaturated dibasic acid, a vinyl ester of a short chainfatty acid and an alpha beta unsaturated aldehyde or ketone, and thenreacting the resulting copolymer with a long chain tertiary alkylprimary amine. Suitable 2 vinyl esters include vinyl acetate and vinylpropionate. The dibasic acid ester may be a maleate, fumarate,itaconate, aconitate, or the like.

The dibasic acid ester component of the copolymer is preferably an esterof fumaric acid or of mixed fumaric and maleic acids and a long chainalcohol of from about 8 to 24 carbon atoms such as octyl (C lauryl (Ctridecyl (C arachidyl (C behenyl (C or tallow (C alcohols produced bythe hydrogenation of tallow acids. The alpha beta unsaturated aldehydeor ketone is one having the general structure:

H RC=(il|J-B" 0 wherein R is selected from the class consisting ofhydrogen, aliphatic groups of from 1 to 8 carbon atoms, phenyl groupsand alkyl phenyl groups of from 1 to 3 alkyl carbon atoms, and R and R"are selected from the class consisting of hydrogen and aliphatic groupsof from 1 to 3 carbon atoms. Among the aldehydes or ketones that may beemployed are included acrolein, cinnamaldehyde, benzalacetone and methylvinyl ketone.

Preferably the copolymers are prepared from mixtures of the monomers inthe proportion of about 1 to 1.5 moles of vinyl ester, about 0.5 to 0.7mole of dibasic acid ester and about 0.3 to 0.5 mole of the aldehyde orketone. The polymerization is conducted in a solution of benzene orother solvent, e.g., xylene, toluene, etc. percent by Weight) attemperatures of to 212 F. and may be promoted by gamma radiation or byuse of a peroxide type catalyst such as benzoyl peroxide, ahydroperoxide or an azo catalyst such asalpha-alphaazo-bis-iso-butyronitrile. The polymerization is conducteduntil a product of 1000 to 100,000 but preferably 2000 to 20,000Staudinger molecular weight is produced.

The copolymer product after boiling off the solvent is then reacted witha long chain tertiary alkyl amine by mixing the product with from 1 to 3moles, preferably 1.25-2.5 moles of amine per mole of aldehyde or ketogroup in the copolymer, the mixture being dissolved in some suitablenon-aqueous high boiling solvent, e.g. toluene, xylene. The mix is thenrefluxed at a temperature of 212-350 F., preferably 230300 F., for aperiod of 1-10 hours, preferably 2-6 hours in a nitrogen atmosphere inthe presence of a catalyst, such as 110% (based on the polymer) of amildly acidic catalyst such as zinc or aluminum chloride. The product isfiltered, the solvent and excess amine are removed by evaporation in avacuum and the polymer is redissolved in the desired solvent. In thereaction, the amine group reacts with the aldehyde or keto group of thepolymer, forming water and an azomethine group C=N-R. The water isremoved by distillation or by absorption by the catalyst. The long chainarnines employed in this inv vention are those having from about 8 toabout 20 carbon 'atoms. Among the amines that may be used are tertiaryoctyl primary, amine, tertiary dodecyl primary amine, and Primene 81Rwhich is a mixture of tertiary alkyl primary amines of 15 to 18 carbonatoms.

The following examples will serve to illustrate this invention.

EXAMPLE 1 EXAMPLE 2 The same procedure as Example 1 was followed,substituting methylvinyl ketone for the cinnamaldehyde. Mole ratios,concentrations, catalyst and reactions times and temperatures were thesame as in Example 1.

EXAMPLE 3 Employing the same procedure as in Example 1 a related productwas prepared'in which crotonaldehyde was substituted for thecinnamaldehyde. Again the same mole'r'atios, concentrations, catalystsand reaction conditionswere used.

' EXAMPLE 4 A commercial fuel oil was selected for stability tests usingthe oil itself as Well as blends of the oil containing various of theadditives described in the foregoing examples; The oil was a blend of 50percent virgin distillate and 50'percent cracked stock. Typicalinspections of this type of oil are as follows:

Gravity, API' 30-33 To various samples of, the fuel oil were added thematerials set forth in Table I below. The base fuel and each of theadditive blends were subjected to a stability test which consisted instoring the fuel oil for a period of 16 hours While maintaining thetemperature at 210 F. At the end of the 16 hours the fuel oil wasfiltered and the amount ofsediment that had been formed during thestorage period was quantitatively determined. The color stabilityof thevarious fuel. oil samples was also deter rninedhy measuring the amountof white light that could be transmitted through each of the filteredsamples after the storage test relative to the amount of the same whitelight that could be transmitted through the unheated,

uninhibited base fuel.

Table I sets forth the data obtained in these tests:

Table I ACCELERATED STORAGE STABILITY TEST- Insoluble Sediment FormedPercent Additive After 16 Hours Color 210 F., Hold rug/600 g. Oil

None 12. 6 71 0.01%ot Product of Example 1.- 1. 4 81 0.01% of Product ofExample 2 1. 2 83 0.01% of Product of Example 3 0.9 82

Percent transmission of white light through filtrate from 16 hour- 210sediment test, relative to unheated, uninhibited base fuel.

It will be noted from the data in Table I that each of these polymerswas very effective in reducing the sediment-forming tendency, as 'Wellas preventing degradation of the fuel oil, as indicated by the colorhold test.

It is not intended that this invention be limited to the.

specific examples presented by way of illustration. The scope of theinvention is limited only by the appended claims.

What is claimed is:

1. A stabilized hydrocarbon oil composition consisting of a majorproportion of hydrocarbons boiling in the range of fromabout 350.F. toabout 900 F., and a minor proportion of a reaction product of a longchain tertiary alkyl primary amine with a copolymer of a vinyl ester ofa short'chain fatty acid, along chain alcohol ester of a conjugatedunsaturated dibasic acid, and a compound selected from the class ofalpha, beta unsaturated aldehydes and ketones having the generalstructure:

wherein R is selected from the class consistingof hydrogen, aliphaticgroups of from 1 to 8 carbon atoms, phenyl groups and alkyl phenylgroups of from 1 to 3- alkyl carbon atoms and R and R are selected fromthe class consisting of'hydrogen and aliphatic hydrocarbon groups offrom 1m 3 carbon atoms, said copolymer being prepared from monomers inproportion of from about 1 to 1.5 molesof vinyl ester, from 0.5 to about0.7 mole of the dibasic acid ester and from about 0.3 to 0.5 mole ofsaid compound by heating at a temperature in the range from about 60 F.to 212 F. to produce a copolymer having a molecular weight in the rangefrom 1,000 to 100,000, and said reaction product'being prepared'byheating at a temperature in the range of about 212 F. to 350 F. for aperiod of 1 to 10 hours, 1 to 3 moles of said amine per one mole of saidcompound in said copolymer, said reaction product being present in saidhydrocarbon oil composition in an amount sufiicient to inhibit theformation of sediment in the said oil.

2. Composition as defined by claim 1 wherein the concentration of'thereaction product in the hydrocarbon oil composition is within the rangeof about 0.001% and about 0.2%. V

3. Composition as defined by claim 1 wherein the long References Citedin the file of this patent UNITED STATES PATENTS 2,122,707 'Balthis July5, 1938 2,353,192 Sargent et al. July 11, 1944 2,387,501 Dietrich Oct.23, 1945 2,457,279 Scott Dec. 28, 1948 2,469,737 McNab et al May '10,1949 2,583,204 Bevan et al. Jan. 22, 1952 2,737,452 Catlin et al. Mar.6, 1956 2,771,348 Meguerian Nov. 20,- 1956 2,793,943 Moore May 28, 19572,800,452 Bondi et al. July' 23, 1957 FOREIGN PATENTS 523,748 1 BelgiumNov. 14, 1953

1. A STABILIZED HYDROCARBON OIL COMPOSITION CONSISTING OF A MAJORPROPORTION OF HYDROCARBONS BOILING IN THE RANGE OF FROM ABOUT 350* F. TOABOUT 900* F., AND A MINOR PROPORTION OF A REACTION PRODUCT OF A LONGCHAIN TERTIARY ALKYL PRIMARY AMINE WITH A COPOLYMER OF A VINYL ESTER OFA SHORT CHAIN FATTY ACID, A LONG CHAIN ALCOHOL ESTER OF A CONJUGATEDUNSATURATED DIBASIC ACID, AND A COMPOUND SELECTED FROM THE CLASS OFALPHA, BETA UNSATURATED ALDEHYDES AND KETONES HAVING THE GENERALSTRUCTURE: